This invention relates to surgical fastener apparatus, and more particularly to surgical fasteners of plastic or plastic-like materials. The invention also relates to apparatus for applying such surgical fasteners to body tissue.
Surgical stapling has been developed to avoid the difficulty of applying individual sutures of thread, gut, wire, or the like. Surgical stapling devices allow the surgeon to fasten body tissue by applying surgical staples singly in succession or simultaneously in parallel, depending on the stapling instrument. The surgical staples are typically metal wire which is usually an inert material such as tantalum or stainless steel, although metals such as magnesium which are gradually absorbed by the body are also known.
In some surgical procedures it is desirable to use non-metallic sutures. For example, it is possible for the presence of metal staples in the body to scatter X rays and thereby degrade the quality of a radiograph. And in some cases metal staples may migrate undesirably in the body during the months or years following the surgery. For these and other reasons it may be desirable to use non-metallic suture materials such as natural or synthetic polymers or resins or collagen which do not impede the transmission of X rays, and which may also be absorbed relatively rapidly by the body. For convenience herein and in the appended claims, all such non-metallic suture materials which are suitable for use in the practice of the present invention will be referred to as "plastic-like materials". To be suitable for use in the present invention, the suture material must be relatively flexible and elastic, and the term "plastic-like materials" as used herein is therefore limited to such materials. However, this term is not limited with respect to biological absorbability, and the "plastic-like materials" referred to herein may therefore be either absorbable or non-absorbable.
The plastic-like materials mentioned above generally have physical properties which are substantially different from the physical properties of metal. These plastic-like materials generally do not lend themselves to substitution for the metal wire in surgical stapling apparatus because fastener structures of these materials are usually not strong enough or rigid enough to pierce or penetrate the tissue to be fastened. Fastener structures of these materials also cannot be bent or crimped during application in the same way that metal staples can be bent or crimped. These materials are generally too flexible to hold a finished staple shape.
It is therefore an object of this invention to provide improved surgical fastening apparatus.
It is a more particular object of this invention to provide improved surgical fasteners of plastic-like materials, and also to provide improved apparatus for applying such fasteners.